Device for holding doctor blades

ABSTRACT

A device for holding doctor blades which are employed for example, in printing, paper coating, textile and similar machines includes first and second clamping members which together define a receiving recess for accommodating a doctor blade. The clamping members are held together in a clamped position by spring means in the form of disc plates or spring plate members. The clamping pressure may be removed by engaging one of the members at a location spaced from the holding springs and spaced from a pivot member which is disposed between the two plates so as to cause one of the members to pivot in respect to the other. For this purpose, one of the members is provided with a bevel on a surface leading away from the pivot so that it may be pressed at its outer end to cause separation of the upper end for the reception of a doctor blade. A device for effecting the pivotal movement of doctor blade clamping members includes a clamping bolt which is engageable through a slot of one of the members into a recess adjacent the bevelled surface of the other and it includes a widened head to engage behind the pivotal member. A fluid pressure-operated piston is connected to the member for the purpose of applying a compressive force to open the clamping elements defined by the first and second members to permit insertion of the doctor blade. The doctor blade, itself, advantageously includes handle means associated therewith to permit it to be lifted and positioned over the movable bolt of the opening device in a position such that it can be operated upon to open the elements to receive the doctor blade.

United States Patent 54 DEVICE FORTTOLDING DOCTOR BLADES 9 Claims, 6 Drawing Figs.

52 U.S.Cl 118/100,

15/236 R, l5/256.5l s11 1m.c1 ..B0s11 04 s01 FieldofSearch 118/100;

[56] References Cited UNITED STATES PATENTS 2,477,339 7/1949 Ljungquist l5/256.51 3,010,134 1l/1961 Goyette 15/236 3,134,126 5/1964 Phillips l5/256.51 3,164,492 1/1965 Schmitt et al 118/100 Primary Examiner-Louis K. Rimrodt Attorney-McGlew and Toren ABSTRACT: A device for holding doctor blades which are employed for example, in printing, paper coating, textile and similar machines includes first and second clamping members which together define a receiving recess for accommodating a doctor blade. The clamping members are held together in a clamped position by spring means in the form of disc plates or spring plate members. The clamping pressure may be removed by engaging one of the members at a location spaced from the holding springs and spaced from a pivot member which is disposed between the two plates so as to cause one of the members to pivot in respect to the other. For this purpose, one of the members is provided with a bevel on a surface leading away from the pivot so that it may be pressed at its outer end to cause separation of the upper end for the reception of a doctor blade. A device for effecting the pivotal movement of doctor blade clamping members includes a clamping bolt which is engageable through a slot of one of the members into a recess adjacent the bevelled surface of the other and it includes a widened head to engage behind the pivotal member. A fluid pressure-operated piston is connected to the member for the purpose of applying a compressive force to open the clamping elements defined by the first and second members to permit insertion of the doctor blade. The doctor blade, itself, advantageously includes handle means associated therewith to permit it to be lifted and positioned over the movable bolt of the opening device in a position such that it can be operated upon to open the elements to receive the doctor blade.

PATENTED GET 5197i 3,610,20 3

SHEET 2 (IF 3 INVENTO'R: Mm Miiue'a m .-ma- 1 PATENTEDOBT 5197! 3,610,203

SHEET 3 OF 3 INVENTOR Mm! MGLLFR 3y: all X In DEVICE FOR HOLDING DOCTOR BLADES SUMMARY OF THE INVENTION This invention relates in general to the construction of doctor blades and holders therefore, and in particular to a new and useful device for clamping a doctor blade so that it can be mounted for use in association with an apparatus such as a printing, paper coating, or textile machine or the like.

The known doctor blade holders include two plates between which the doctor blade is held by clamping elements in the form of a large number of clamping screws or bolts. In order to insert a cleaned or a new blade it is necessary to loosen all of the screws and then to tighten them again and this takes a considerable amount of time. A further disadvantage is that it is not possible to tighten all of the screws at exactly the same time. This produces a curvature of the doctor blade so that a uniform bending of the blade edge on the cylinder is not ensured, and as a result, there is an unsatisfactory scraping action. It is also known to provide mounting means in the form of a holder having an opening and closing mouth for receiving the blade which is operated by a handwheel driving through a worm gear. This mechanical device has the disadvantage that the insertion of the doctor blade into a correct position can only be effected approximately. The correct position is only achieved by turning the handwheel and pressing down the doctor blade on the circumferential surface of the form cylinder. Such an arrangement is time-consuming and encumbersome.

In accordance with the present invention, there is provided a doctor blade holder which eliminates the disadvantages of the prior art and permits the exact clamping of the doctor blade in a few seconds. The operation is effected by means of a clamping device associated with the holder which can be operated, for example by a foot pedal so that the blade may be held while the clamping is effected. The doctor blade holder for this purpose includes first and second clamping members one of which may be moved at one end toward the other for pivoting the opposite end about a fulcrum to open the clamping jaws for receiving the doctor blade. The one of the clamping elements which is movable for pivoting purposes includes a recess for engaging a bolt member therebehind. The bolt member may be moved such as by a fluid-pressure piston and cylinder mechanism for the purposes of opening the clamping member. The opening device advantageously is operated by a foot pedal and the doctor blade clamping holder is provided with a handle such that it may be inserted into the opening device in a simple manner. The action is similar to the action of a clothes pin and the device for openingthe clamping jaws of the pin includes a bolt member which is connected to a fluid piston which is movable in a fluid cylinder under the control of a control member such as a foot pedal.

Accordingly, it is an object of the invention to provide an improved holder for a doctor blade which includes first and second clamping members which are pivoted together, with one being movable relative to the other in order to pivot the opposite ends of the clamping members so that they open to receive the doctor blade, the construction advantageously includes elements in the form of plates which have a receiving recess defined therethrough for permitting the engagement of an opening bolt member which may be moved by fluid pressure to cause the pivotal movement of the two clamping elements.

A further object of the invention is to provide a clamping device for holding a doctor blade which may be pivoted open in a simple manner and which includes handle means for positioning the device in association with an opening mechanism.

A further object of the invention is to provide a doctor bladeholder which is simple in design, rugged in construction, and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims anunderstanding of the invention, its operating advantages and specific objects attained by its use reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of 5 the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a partial side elevational view and partial sectional view of a doctor blade clamping device and an opening apparatus associated therewith as constructed in accordance with the invention;

FIG. 2 is a side elevational view of the opening apparatus;

FIG. 3 is a side elevational view of the clamping device;

FIG. 4 is a side elevational view of the clamping device and opening apparatus;

FIG. 5 is a partial front elevational view of the clamping device and opening device; and

FIG. 6 is a partial top plan view of the clamping device and opening device.

GENERAL DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in particular, the invention em- In accordance with the invention, the holder includes a pair of clamping plate elements in the form of a short clamp plate element 1 and a larger clamp plate element 2. One of the clamp plate elements 1 and 2, in this embodiment, the element 2 has a surface 5 which is adjacent a pivot member 4 which is bevelled so as to define a closing slot 54 between the plate elements at the ends opposite to a receiving recess or clamping jaw 23 for a doctor blade 14.

The clamping plates 1 and 2 are held together in a clamping relationship by means of a spring assembly generally designated 8 which includes disc or cup springs arranged around a bolt member 6 which is threaded into the plate 1 and is received in a bore 7 of the plate 2. Tension on the spring assembly 8 is set in accordance with the tightening of a nut member on the bolt 6. The bore 7 is made sufficiently large to permit movement of the plate 2 relative to the bolt 6. A washer or disc 9 is arranged between an adjusting nut 10 and the springs 8.

The fulcrum or pivot point is defined by a bar 11 which is in- 50 serted into a circular recess defined by two half circular porwithdrawal thereof. The holder 50 includes a handle 22 which may be engaged by an operator to permit lifting of the holder and the positioning of the holder in association with the apparatus 52 for opening and closing the clamping elements thereof.

The device 52 for opening and closing the plates 1 and 2 to facilitate insertion or removal of the doctor blade 14 includes a frame 13 having a supporting base 15 and which provides a mounting for one or more fluid cylinders 16. Each fluid cylinder 16 carries a movable piston having an arm which is connected to a, holding bolt or clamp actuator 18 which extends outwardly from the frame 13. The frame 13 mounts a positioning member 56 having an end frame 560 which provides a locating guide for an outer face la of the plate I of the holder 50. The bolt member 18 includes a cross plate 18a which is located at a spaced location beyond the guide face 56a in order to permit the plates 1 and 2 to be oriented such that a recess 12 in the plate 1 and an aligned recess 19 in the plate 2 may be oriented to receive the shank portion of the bolt 18 and to position the cross part 18a beyond the end face nexed to and forming a part of this specification. For a better 2a of the plate 2 so as to engage against this end face.

After the carrier 50 is positioned on the opening device 52 in the above manner, a control mechanism in the form of a foot pedal 21 is actuated for communicating a fluid pressure from a line 58 through a line and a further line 17 to the fluid pressure cylinder 16 to cause retraction of the bolt 18. This causes the plate 2 to rotate about the pivot bar 11 to cause the upper end thereof to move away from the plate 1 and to open the receiving jaws 23. The fluid pressure cylinder 16 is advantageously operated by a pneumatic or hydraulic system.

METHOD OF OPERATION In order to clamp a doctor blade 14 in the doctor blade holder 50, the blade 14 is grabbed by the handle 22 and lowered downwardly over the bolt 18 which is accommodated within the recesses 12 and 19. Then the doctor blade, which is cut to the desired length from a bar roller, is held with both hands over the holder 52 and the foot pedal 21 is actuated by the operator's foot. The bolt 18 causes the opening of the two plates 1 and 2 to permit easy admission of the doctor blade 14 into the receiving recess or jaw 23. Thereupon the foot pedal 21 is released to cause the arm 2 to move tightly against the doctor blade and clamp it in position. The blade 14 may be removed in a similar manner and both installation and removal takes only a few seconds. The apparatus includes a plurality of stay bolts 6 which extend across the width of the blade in order to provide a uniform pressure across the whole blade width. The clamping construction is such that a bending or stressing of the blade edge is avoided. In addition, the contact pressure acting on the whole blade is reduced.

What is claimed is:

l. A holder for a doctor blade and the like comprising first and second plate members arranged in a juxtaposed position and defining a doctor blade clamping recess therebetween adjacent one end, means defining a pivot between said first and second plate members, said first and second plate members having opposite ends from said one end which may be moved together for pivoting said one end outwardly to open said recess, and spring means for biasing said one end together to close said recess for clamping engagement of a plate within said recess.

2. A holder, according to claim 1, wherein said spring means includes a bolt extending from one of said plates and through a bore of the other of said plates, said other of said plates being movable relative to said one of said plates when said plates are pivoted about said pivot, and at least one spring member acting on said movable plate to urge it into engagement with said fixed plate.

3. A holder, according to claim 1, wherein one of said plates is a fixed plate and the other is pivotally movable in respect to said fixed plate, said pivotally movable plate having a bevelled edge adjacent the end thereof which is opposite to said clamping recess end to permit movement of this edge toward said first plate and outward movement of said clamping end.

4. A holder, according to claim 3, wherein said spring means includes a bolt secured to said fixed plate and extending through a bore of said movable plate, and a plurality of spring members engaged around said bolt and biasing said movable plate toward said fixed plate.

5. A holder, according to claim 4, including a plurality of bolt members arranged at spaced locations along the length of said fixed and movable plates.

6. A holder, according to claim 3, including handle means for lifting said holder.

7. A holder, according to claim 1, including an opening mechanism comprising a movable piston member having a portion engaged with one of said plates, and means for moving said piston member to cause the portion engaged with said plate to move said plate in relative to said other plate for opening said clamping recess.

8. A holder, according to claim 7, including .a separate opening device comprising a frame having a guide face said movable piston including a boltlike member extending outwardly from said guide face, said first and second plates having recesses which are aligned and having said bolt member extending through said recesses, said bolt member having a widened end face for engaging the outer one of said plates and for moving it toward the inner one for the purposes of opening the clamping recess therein.

9. A holder, according to claim 8, wherein one of said plates is a fixed plate which is adapted to lie against said guiding face of said opening device, the other of said plates being pivotally movable in respect to said first plate and including a bevelled portion defining a slot between said first and second plate for permitting inward movement of said second plate relative to said first plate said bolt member being engaged with said second plate behind said bevelled portion. 

1. A holder for a doctor blade and the like comprising first and second plate members arranged in a juxtaposed position and defining a doctor blade clamping recess therebetween adjacent one end, means defining a pivot Between said first and second plate members, said first and second plate members having opposite ends from said one end which may be moved together for pivoting said one end outwardly to open said recess, and spring means for biasing said one end together to close said recess for clamping engagement of a plate within said recess.
 2. A holder, according to claim 1, wherein said spring means includes a bolt extending from one of said plates and through a bore of the other of said plates, said other of said plates being movable relative to said one of said plates when said plates are pivoted about said pivot, and at least one spring member acting on said movable plate to urge it into engagement with said fixed plate.
 3. A holder, according to claim 1, wherein one of said plates is a fixed plate and the other is pivotally movable in respect to said fixed plate, said pivotally movable plate having a bevelled edge adjacent the end thereof which is opposite to said clamping recess end to permit movement of this edge toward said first plate and outward movement of said clamping end.
 4. A holder, according to claim 3, wherein said spring means includes a bolt secured to said fixed plate and extending through a bore of said movable plate, and a plurality of spring members engaged around said bolt and biasing said movable plate toward said fixed plate.
 5. A holder, according to claim 4, including a plurality of bolt members arranged at spaced locations along the length of said fixed and movable plates.
 6. A holder, according to claim 3, including handle means for lifting said holder.
 7. A holder, according to claim 1, including an opening mechanism comprising a movable piston member having a portion engaged with one of said plates, and means for moving said piston member to cause the portion engaged with said plate to move said plate in relative to said other plate for opening said clamping recess.
 8. A holder, according to claim 7, including a separate opening device comprising a frame having a guide face said movable piston including a boltlike member extending outwardly from said guide face, said first and second plates having recesses which are aligned and having said bolt member extending through said recesses, said bolt member having a widened end face for engaging the outer one of said plates and for moving it toward the inner one for the purposes of opening the clamping recess therein.
 9. A holder, according to claim 8, wherein one of said plates is a fixed plate which is adapted to lie against said guiding face of said opening device, the other of said plates being pivotally movable in respect to said first plate and including a bevelled portion defining a slot between said first and second plate for permitting inward movement of said second plate relative to said first plate said bolt member being engaged with said second plate behind said bevelled portion. 